Data distribution is used to distribute data among multiple data stores or among various locations. One such type of data distribution is referred to as replication. In broad terms, replication involves copying data from one data store to other data stores, such that each of the data stores contains the same data.
Distributed data stores provide a number of benefits over non-distributed data stores. One of the benefits is that the risk of data loss is greatly diminished. If a single server or data store goes down, any of the other data stores are available to provide access to the distributed data. Another benefit of a distributed data store is that the data can be made widely available. For example, information that is needed by everyone in an organization, such as an employee directory, may be made accessible to all employees by replicating the employee directory among various sites.
One example of a distributed data store is the Microsoft® Active Directory® directory service. In such a directory service, data may be distributed between computing systems referred to as domain controllers. When data is modified on one of the domain controllers, the directory service may be configured to replicate that data to other domain controllers. One of the benefits of a directory service is that it simplifies the task of administering security policies in a computer network. Rather than requiring the network administrator to individually set and maintain security policies on each computing system in the network, the directory service enables security policies to be distributed throughout the network. When a change is made to a security policy, a copy of the security policy is replicated between the other domain controllers within the network. In this way a global policy may be defined and maintained that is the same throughout the organization.